How to manage events on a specific div? - javascript

I would like to catch some events for a specific div if the user clicked on the div (focus the div), keyboard events are catch (not if the last click was out of the div (unfocus the div)
I tried some things, but haven't succeeded : JSFiddle
document.getElementById("box").onkeydown = function(event) {
if (event.keyCode == 13) { // ENTER
alert("Key ENTER pressed");
}
}
This code doesn't work even if I click on the div.
Pure JS solution please

The div element isn't interactive content by default. This means that there isn't a case where the return key will ever trigger on it. If you want your div element to be interactive you can give it the contenteditable attribute:
<div id="box" contenteditable></div>
In order to now fire the event you need to first focus the div element (by clicking or tabbing into it). Now any key you press will be handled by your onkeydown event.
JSFiddle demo.

Giving the 'div' a tabindex should do the trick, so the div can have the focus:
<div id="box" tabindex="-1"></div>
If you click on the div it gets the focus and you can catch the event.
JSFIDDEL
If you set 'tabindex' > 0 you can also select the div using TAB.

You could catch all the click events, then check if the event target was inside the div:
var focus_on_div = false;
document.onclick = function(event) {
if(event.target.getAttribute('id') == 'mydiv') {
focus_on_div = true;
} else {
focus_on_div = false;
}
}
document.onkeyup = function(event) {
if (focus_on_div) {
// do stuff
}
}

try this code i hope this work
var mousePosition = {x:0, y:0};
document.addEventListener('mousemove', function(mouseMoveEvent){
mousePosition.x = mouseMoveEvent.pageX;
mousePosition.y = mouseMoveEvent.pageY;
}, false);
window.onkeydown = function(event) {
var x = mousePosition.x;
var y = mousePosition.y;
var elementMouseIsOver = document.elementFromPoint(x, y);
if(elementMouseIsOver.id == "box" && event.keyCode == "13") {
alert("You Hate Enter Dont You?");
}
}
DEMO

Related

Why after adding elements to the document the addEventListener stop working?

I have two .addEvenetListener in my code but one of them stop working after adding a div to my
document.addEventListener("mousemove", (e) => { mouseMove(e) }, false);
document.body.addEventListener("click", function(e){
e = e || window.event;
if (e.which == 1) fire();
}, false);
function fire(){
let bullet = `<div class="bullet" style="left:${shooterPlace.x}px;top:${shooterPlace.y}px;"></div>`;
document.getElementById("space").innerHTML += bullet;
}
After clicking, the GUN that I made stops rotating due to the stop of the eventlistener
HTML:
<div class="body-copier" id="space">
<div id="gun">
<div id="gun-shooter-place"></div>
</div>
</div>
Try this
let bullet = document.createElement("div");
Object.assign(bullet,{class:"bullet",style:`left:${shooterPlace.x}px;top:${shooterPlace.y}px;`});
document.getElementById("space").append(bullet);
Your .space element is edited out of DOM, so it loses it's eventListeners as Your innerHtml+="something new" is the same as .innerHtml="something berfore with something new" .
You want to add additional element to DOm but .innerHtml doesn't do this.
Anyway You didn't provide reproducable code (html missing) so i don't know where is Your gun element (i suppose it's inside .space element)

Check if mouse is inside div

I want to use an if statement to check if the mouse is inside a certain div, something like this:
if ( mouse is inside #element ) {
// do something
} else {
return;
}
This will result in the function to start when the mouse is inside #element, and stops when the mouse is outside #element.
you can register jQuery handlers:
var isOnDiv = false;
$(yourDiv).mouseenter(function(){isOnDiv=true;});
$(yourDiv).mouseleave(function(){isOnDiv=false;});
no jQuery alternative:
document.getElementById("element").addEventListener("mouseenter", function( ) {isOnDiv=true;});
document.getElementById("element").addEventListener("mouseout", function( ) {isOnDiv=false;});
and somewhereelse:
if ( isOnDiv===true ) {
// do something
} else {
return;
}
Well, that's kinda of what events are for. Simply attach an event listener to the div you want to monitor.
var div = document.getElementById('myDiv');
div.addEventListener('mouseenter', function(){
// stuff to do when the mouse enters this div
}, false);
If you want to do it using math, you still need to have an event on a parent element or something, to be able to get the mouse coordinates, which will then be stored in an event object, which is passed to the callback.
var body = document.getElementsByTagName('body');
var divRect = document.getElementById('myDiv').getBoundingClientRect();
body.addEventListener('mousemove', function(event){
if (event.clientX >= divRect.left && event.clientX <= divRect.right &&
event.clientY >= divRect.top && event.clientY <= divRect.bottom) {
// Mouse is inside element.
}
}, false);
But it's best to use the above method.
simply you can use this:
var element = document.getElementById("myId");
if (element.parentNode.querySelector(":hover") == element) {
//Mouse is inside element
} else {
//Mouse is outside element
}
Improving using the comments
const element = document.getElementById("myId");
if (element.parentNode.matches(":hover")) {
//Mouse is inside element
} else {
//Mouse is outside element
}
$("div").mouseover(function(){
//here your stuff so simple..
});
You can do something like this
var flag = false;
$("div").mouseover(function(){
flag = true;
testing();
});
$("div").mouseout(function(){
flag = false;
testing();
});
function testing(){
if(flag){
//mouse hover
}else{
//mouse out
}
}

Correct way to prevent triggering `click` if inner element is not hovered when mouse is released

I need to prevent hiding of a modal dialog when user clicks on the dialog, then moves the mouse outside of the dialog, and releases it. The dialog is placed inside outer div on which the click event is registered. Here is the example of the modal dialog and its setup.
So I've done the following:
var pointerDownElement = null;
$('.d1').on('mousedown', function(event) {
// this is how I do it to prevent triggering of click event
pointerDownElement = event.target;
// this is how a browser does it
pointerDownElement = event.currentTarget;
});
$('.d1').on('mouseup', function(event) {
var element = event.target;
if (element === pointerDownElement) {
console.log('triggering click');
}
});
Is this approach correct?
You're definitely on the right track. Slightly modified code:
var pointerDownElement = null;
$('.d1').on('mousedown', function(event) {
event.preventDefault();
pointerDownElement = event.currentTarget;
return false;
});
$('.d1').on('mouseup', function(event) {
if (event.target=== pointerDownElement) {
console.log('triggering click');
}
});
No need to assign a value to a variable if you're only going to use it once. Also, event.preventDefault(); and return false; will guarantee the default behavior of the event doesn't take place (not that there typically is one for mousedown, but I'm assuming you have a reason for including this code).

Prevent a click handler from firing when an inner div is clicked

I believe my question is the reverse of this one: Prevent execution of parent event handler
I'm building a UI in Google Apps Script. I have a select box, inside a larger container div. I want to be able to run an animation using jQuery when the parent div is clicked, but I don't want the animation to run when the select box is clicked. I tried using stopPropagation, but that's not helping. Currently the animation runs when either the div itself, or the select drop-down is clicked:
var ISDOWN = true; //global to track whether div is down or up
$("#outer-container").click(
function(e) {
e.stopPropagation();
var source = $(this).attr('id');
if (source === "outer-container"){
if (ISDOWN === true){
$("#outer-container").animate({top: "8px"});
ISDOWN = false;
}
else {
$("#outer-container").animate({top: "45px"});
ISDOWN = true;
}
}
});
You can check the element being clicked from the target property on the event object
if ($(e.target).attr('id') === 'outer-container') {
if (ISDOWN === true){
$("#outer-container").animate({top: "8px"});
ISDOWN = false;
}
else {
$("#outer-container").animate({top: "45px"});
ISDOWN = true;
}
}

JavaScript: Check if mouse button down?

Is there a way to detect if a mouse button is currently down in JavaScript?
I know about the "mousedown" event, but that's not what I need. Some time AFTER the mouse button is pressed, I want to be able to detect if it is still pressed down.
Is this possible?
Regarding Pax' solution: it doesn't work if user clicks more than one button intentionally or accidentally. Don't ask me how I know :-(.
The correct code should be like that:
var mouseDown = 0;
document.body.onmousedown = function() {
++mouseDown;
}
document.body.onmouseup = function() {
--mouseDown;
}
With the test like this:
if(mouseDown){
// crikey! isn't she a beauty?
}
If you want to know what button is pressed, be prepared to make mouseDown an array of counters and count them separately for separate buttons:
// let's pretend that a mouse doesn't have more than 9 buttons
var mouseDown = [0, 0, 0, 0, 0, 0, 0, 0, 0],
mouseDownCount = 0;
document.body.onmousedown = function(evt) {
++mouseDown[evt.button];
++mouseDownCount;
}
document.body.onmouseup = function(evt) {
--mouseDown[evt.button];
--mouseDownCount;
}
Now you can check what buttons were pressed exactly:
if(mouseDownCount){
// alright, let's lift the little bugger up!
for(var i = 0; i < mouseDown.length; ++i){
if(mouseDown[i]){
// we found it right there!
}
}
}
Now be warned that the code above would work only for standard-compliant browsers that pass you a button number starting from 0 and up. IE uses a bit mask of currently pressed buttons:
0 for "nothing is pressed"
1 for left
2 for right
4 for middle
and any combination of above, e.g., 5 for left + middle
So adjust your code accordingly! I leave it as an exercise.
And remember: IE uses a global event object called … "event".
Incidentally IE has a feature useful in your case: when other browsers send "button" only for mouse button events (onclick, onmousedown, and onmouseup), IE sends it with onmousemove too. So you can start listening for onmousemove when you need to know the button state, and check for evt.button as soon as you got it — now you know what mouse buttons were pressed:
// for IE only!
document.body.onmousemove = function(){
if(event.button){
// aha! we caught a feisty little sheila!
}
};
Of course you get nothing if she plays dead and not moving.
Relevant links:
MouseEvent's button (DOM 2)
MSDN's button
Update #1: I don't know why I carried over the document.body-style of code. It will be better to attach event handlers directly to the document.
This is an old question, and the answers here seem to mostly advocate for using mousedown and mouseup to keep track of whether a button is pressed. But as others have pointed out, mouseup will only fire when performed within the browser, which can lead to losing track of the button state.
However, MouseEvent (now) indicates which buttons are currently pushed:
For all modern browsers (including Safari v11.1+ [v11.3+ on iOS]), use MouseEvent.buttons
For Safari < 11.1 (11.3 on iOS), use MouseEvent.which (buttons will be undefined for Safari) Note: which uses different numbers from buttons for Right and Middle clicks.
When registered on document, mousemove will fire immediately as soon as the cursor reenters the browser, so if the user releases outside then the state will be updated as soon as they mouse back inside.
A simple implementation might look like:
var primaryMouseButtonDown = false;
function setPrimaryButtonState(e) {
var flags = e.buttons !== undefined ? e.buttons : e.which;
primaryMouseButtonDown = (flags & 1) === 1;
}
document.addEventListener("mousedown", setPrimaryButtonState);
document.addEventListener("mousemove", setPrimaryButtonState);
document.addEventListener("mouseup", setPrimaryButtonState);
That code tracks the state of the primary mouse button (typically the left), ignoring the state of other mouse buttons.
If more complicated scenarios are required (different buttons/multiple buttons/control keys), check out the MouseEvent docs.
I think the best approach to this is to keep your own record of the mouse button state, as follows:
var mouseDown = 0;
document.body.onmousedown = function() {
mouseDown = 1;
}
document.body.onmouseup = function() {
mouseDown = 0;
}
and then, later in your code:
if (mouseDown == 1) {
// the mouse is down, do what you have to do.
}
the solution isn't good.
one could "mousedown" on the document, then "mouseup" outside the browser, and on this case the browser would still be thinking the mouse is down.
the only good solution is using IE.event object.
I know this is an old post, but I thought the tracking of mouse button using mouse up/down felt a bit clunky, so I found an alternative that may appeal to some.
<style>
div.myDiv:active {
cursor: default;
}
</style>
<script>
function handleMove( div ) {
var style = getComputedStyle( div );
if (style.getPropertyValue('cursor') == 'default')
{
// You're down and moving here!
}
}
</script>
<div class='myDiv' onmousemove='handleMove(this);'>Click and drag me!</div>
The :active selector handles the mouse click much better than mouse up/down, you just need a way of reading that state in the onmousemove event. For that I needed to cheat and relied on the fact that the default cursor is "auto" and I just change it to "default", which is what auto selects by default.
You can use anything in the object that is returned by getComputedStyle that you can use as a flag without upsetting the look of your page e.g. border-color.
I would have liked to set my own user defined style in the :active section, but I couldn't get that to work. It would be better if it's possible.
If you're working within a complex page with existing mouse event handlers, I'd recommend handling the event on capture (instead of bubble). To do this, just set the 3rd parameter of addEventListener to true.
Additionally, you may want to check for event.which to ensure you're handling actual user interaction and not mouse events, e.g. elem.dispatchEvent(new Event('mousedown')).
var isMouseDown = false;
document.addEventListener('mousedown', function(event) {
if ( event.which ) isMouseDown = true;
}, true);
document.addEventListener('mouseup', function(event) {
if ( event.which ) isMouseDown = false;
}, true);
Add the handler to document (or window) instead of document.body is important b/c it ensures that mouseup events outside of the window are still recorded.
The following snippet will attempt to execute the "doStuff" function 2 seconds after the mouseDown event occurs in document.body. If the user lifts up the button, the mouseUp event will occur and cancel the delayed execution.
I'd advise using some method for cross-browser event attachment - setting the mousedown and mouseup properties explicitly was done to simplify the example.
function doStuff() {
// does something when mouse is down in body for longer than 2 seconds
}
var mousedownTimeout;
document.body.onmousedown = function() {
mousedownTimeout = window.setTimeout(doStuff, 2000);
}
document.body.onmouseup = function() {
window.clearTimeout(mousedownTimeout);
}
In case someone else runs into this, you can use .matches with the :active selector:
function mouseDown() {
return document.body.matches(":active");
}
Using the MouseEvent api, to check the pressed button, if any:
// Mouse buttons
document.addEventListener('mousedown', e => console.log(e.buttons))
// Keyboard keys
document.addEventListener('keydown', e => console.log(e.key))
Return:
A number representing one or more buttons. For more than one button
pressed simultaneously, the values are combined (e.g., 3 is primary +
secondary).
0 : No button or un-initialized
1 : Primary button (usually the left button)
2 : Secondary button (usually the right button)
4 : Auxilary button (usually the mouse wheel button or middle button)
8 : 4th button (typically the "Browser Back" button)
16 : 5th button (typically the "Browser Forward" button)
You can combine #Pax and my answers to also get the duration that the mouse has been down for:
var mousedownTimeout,
mousedown = 0;
document.body.onmousedown = function() {
mousedown = 0;
window.clearInterval(mousedownTimeout);
mousedownTimeout = window.setInterval(function() { mousedown += 200 }, 200);
}
document.body.onmouseup = function() {
mousedown = 0;
window.clearInterval(mousedownTimeout);
}
Then later:
if (mousedown >= 2000) {
// do something if the mousebutton has been down for at least 2 seconds
}
You need to handle the MouseDown and MouseUp and set some flag or something to track it "later down the road"... :(
Short and sweet
I'm not sure why none of the previous answers worked for me, but I came up with this solution during a eureka moment. It not only works, but it is also most elegant:
Add to body tag:
onmouseup="down=0;" onmousedown="down=1;"
Then test and execute myfunction() if down equals 1:
onmousemove="if (down==1) myfunction();"
Using jQuery, the following solution handles even the "drag off the page then release case".
$(document).mousedown(function(e) {
mouseDown = true;
}).mouseup(function(e) {
mouseDown = false;
}).mouseleave(function(e) {
mouseDown = false;
});
I don't know how it handles multiple mouse buttons.
If there were a way to start the click outside the window, then bring the mouse into the window, then this would probably not work properly there either.
As said #Jack, when mouseup happens outside of browser window, we are not aware of it...
This code (almost) worked for me:
window.addEventListener('mouseup', mouseUpHandler, false);
window.addEventListener('mousedown', mouseDownHandler, false);
Unfortunately, I won't get the mouseup event in one of those cases:
user simultaneously presses a keyboard key and a mouse button, releases mouse button outside of browser window then releases key.
user presses two mouse buttons simultaneously, releases one mouse button then the other one, both outside of browser window.
var mousedown = 0;
$(function(){
document.onmousedown = function(e){
mousedown = mousedown | getWindowStyleButton(e);
e = e || window.event;
console.log("Button: " + e.button + " Which: " + e.which + " MouseDown: " + mousedown);
}
document.onmouseup = function(e){
mousedown = mousedown ^ getWindowStyleButton(e);
e = e || window.event;
console.log("Button: " + e.button + " Which: " + e.which + " MouseDown: " + mousedown);
}
document.oncontextmenu = function(e){
// to suppress oncontextmenu because it blocks
// a mouseup when two buttons are pressed and
// the right-mouse button is released before
// the other button.
return false;
}
});
function getWindowStyleButton(e){
var button = 0;
if (e) {
if (e.button === 0) button = 1;
else if (e.button === 1) button = 4;
else if (e.button === 2) button = 2;
}else if (window.event){
button = window.event.button;
}
return button;
}
this cross-browser version works fine for me.
Below jQuery example, when mouse is over $('.element'), color is changing depending on which mouse button is pressed.
var clicableArea = {
init: function () {
var self = this;
('.element').mouseover(function (e) {
self.handlemouseClick(e, $(this));
}).mousedown(function (e) {
self.handlemouseClick(e, $(this));
});
},
handlemouseClick: function (e, element) {
if (e.buttons === 1) {//left button
element.css('background', '#f00');
}
if (e.buttons === 2) { //right buttom
element.css('background', 'none');
}
}
};
$(document).ready(function () {
clicableArea.init();
});
Well, you can't check if it's down after the event, but you can check if it's Up... If it's up.. it means that no longer is down :P lol
So the user presses the button down (onMouseDown event) ... and after that, you check if is up (onMouseUp). While it's not up, you can do what you need.

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